Question: Which of the following numbers is a factor of 192? ${4,5,9,11,14}$
Answer: By definition, a factor of a number will divide evenly into that number. We can start by dividing $192$ by each of our answer choices. $192 \div 4 = 48$ $192 \div 5 = 38\text{ R }2$ $192 \div 9 = 21\text{ R }3$ $192 \div 11 = 17\text{ R }5$ $192 \div 14 = 13\text{ R }10$ The only answer choice that divides into $192$ with no remainder is $4$ $ 48$ $4$ $192$ We can check our answer by looking at the prime factorization of both numbers. Notice that the prime factors of $4$ are contained within the prime factors of $192$ $192 = 2\times2\times2\times2\times2\times2\times3 4 = 2\times2$ Therefore the only factor of $192$ out of our choices is $4$. We can say that $192$ is divisible by $4$.